I have an iBook G4 that was running 10.4.10 and it suddenly wouldn't start up. Long story short is that I ended up having to do an archive and install (back to 10.4.7) to get it running again and now it appears to be working well. The archive and install created that "Previous System" folder so I'm wondering if that is needed for anything? I ran software update and am now running on 10.4.10 again. I would like to get rid of the previous system folder because it is taking up over 8 GB of space. Thanks in advance for any information.